Set Blueprint class in Unreal editor to spawn it using C++

Development Programming & Scripting C++
,
1

Hi!

I’m using Unreal 5.1.1.

I want to spawn Blueprint actors in C++ with this code.

Header file:

UPROPERTY(EditDefaultsOnly, Category = "Planetarium")
class AStarActor* BlueprintStar;

Code file:

void AStarsSphereActor::ShowStars(TArray<FStar> Stars)
{
	if ((BlueprintStar) && (Stars.Num() > 0))
	{
		const FAttachmentTransformRules AttachmentTransformRules =
			FAttachmentTransformRules(EAttachmentRule::KeepWorld, true);

		for (FStar& star : Stars)
		{
			FVector Location;

			Location.X = star.SphereLocation.X;
			Location.Y = star.SphereLocation.Y;
			Location.Z = star.SphereLocation.Z;

			AActor* StarActor =
				GetWorld()->SpawnActor(
					UGameplayStatics::GetObjectClass(BlueprintStar), &Location);

			StarActor->AttachToComponent(RootComponent, AttachmentTransformRules);
		}
	}
}

But I need to have a BP_Star object inside the level to use it.

I only wanted to know how to set the Blueprint class of the BP_Star in the Blueprint class that inherit from AStarsSphereActor.

How can I do it?

Thanks

2

Maybe you should write like this:

UPROPERTY(EditInstanceOnly, Category = Components)
TSubclassOf<class AStarActor> BlueprintStar;|

and

if (*BlueprintStar)
{
  ***
  SpawnActor(BlueprintStar->Get(), &Location);
  ***
}
3

Thanks, but there is a for:

for (FStar& star : Stars)

I want to set the Blueprint class in the editor to know which kind of class I have to spawn N times.

Thanks.

4

header:

UPROPERTY(EditInstanceOnly, Category = Components)
TSubclassOf<class AStarActor> BlueprintStar;

cpp:

void AStarsSphereActor::ShowStars(TArray<FStar> Stars)
{
	if (*BlueprintStar)
	{
		const FAttachmentTransformRules AttachmentTransformRules =
			FAttachmentTransformRules(EAttachmentRule::KeepWorld, true);

		for (FStar& star : Stars)
		{
			FVector Location;

			Location.X = star.SphereLocation.X;
			Location.Y = star.SphereLocation.Y;
			Location.Z = star.SphereLocation.Z;

			AActor* StarActor =
				GetWorld()->SpawnActor(
					BlueprintStar->Get(), &Location);

			StarActor->AttachToComponent(RootComponent, AttachmentTransformRules);
		}
	}
}

You can set the property “BlueprintStar” in the editor to specify a BP class that inherit from AStarActor.

By the way, you can also replace the class AStarActor with other classes.